GRB 230510A
GCN Circular 33880
Subject
GRB 230510A: Swift-BAT refined analysis
Date
2023-05-26T13:27:36Z (3 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), R. A. J. Eyles-Ferris (U Leicester),
H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+349 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230510A (trigger #1167973)
(Eyles-Ferris, et al., GCN Circ. 33752). The BAT ground-calculated position is
RA, Dec = 318.138, 34.430 deg which is
RA(J2000) = 21h 12m 33.2s
Dec(J2000) = +34d 25' 49.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a precursor starting at T-150 s with
a duration of ~20 s. The bright main episode starts at T-10 s, peaks at
T+15 s, and ends at T+60 s. T90 (15-350 keV) is 178.4 +- 6.9 sec
(estimated error including systematics).
The time-averaged spectrum from T-145.6 to T+56.8 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.60 +- 0.09. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+13.39 sec in the 15-150 keV band
is 5.9 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1167973/BA/
GCN Circular 33794
Subject
GRB 230510A: GRBAlpha detection
Date
2023-05-14T08:25:50Z (3 years ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 230510A (Fermi/GBM detection: GCN 33751; Swift/BAT detection: GCN 33752; CALET/CGBM detection: GCN 33762; Wind/Konus detection at 2023-05-10 12:06:42.814 UT; INTEGRAL/SPI-ACS detection at 2023-05-10 12:06:43 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:2302.10048).
The detection was confirmed at the peak time 2023-05-10 12:06:31 UTC. The T90 duration measured by GRBAlpha is 24 s and the overall significance during T90 reaches 6.6 sigma in the 120-400 keV band.
The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB230510A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN Circular 33790
Subject
GRB 230510A: OHP/T193 and OHP/T120 optical observations
Date
2023-05-13T08:39:57Z (3 years ago)
From
Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com>
B. Schneider (MIT), C. Adami (LAM/Pytheas/AMU), J. T. Palmerio (GEPI,
Obs. de Paris), S. Basa (LAM), E. Le Floc'h, D. Götz (CEA Paris-Saclay),
S. D. Vergani (GEPI, Obs. de Paris), C. Barthelemy, Q. Desvigne,
J. Latour (AMU), D. Turpin (CEA Paris-Saclay), report on behalf of a
larger collaboration:
We observed the field of GRB 230510A (Fermi GBM team, GCN 33751; Eyles-Ferris
et al., GCN 33752) using the T193cm and T120cm telescopes at Observatoire de
Haute-Provence (France) respectively equipped with the MISTRAL spectro-imager
and the T120 CCD camera. A total of 8 exposures were obtained in the imaging
mode of MISTRAL in the r-band filter (6x600s + 2x300s) and 50 exposures
were obtained with the T120 CCD camera in the r-band filter (50x90s).
Observations were made from 2023 11 May 01:24:26 UT to 2023 11 May 03:00:47 UT
(mid time ~13.2h after trigger).
In the combined frames, we detect a faint source consistent with the
X-ray afterglow position reported by Evans et al. (GCN 33756) and
with the optical afterglow position reported by Jiang et al. (GCN 33761).
The source is detected by both instruments at the same position.
Combining the MISTRAL and T120 images, we measured a magnitude of
r = 21.8 +/- 0.2, in agreement with the value determined individually for
each instrument. The faintest PanStarr DR1 object detected at 3 sigma
in the combined image is at r = 22. The photometric calibration was
performed using nearby stars from the PS1 catalog and the magnitude
is not corrected for Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence,
in particular Jean Balcaen for the MISTRAL observations, Yoann Degot-Longhi,
Stephane Favard, Luc Favre, and Christelle Eyraud for the T120 observations.
GCN Circular 33777
Subject
GRB 230510A: GIT optical upper limits
Date
2023-05-12T11:26:15Z (3 years ago)
From
Vishwajeet Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>
V. Swain (IITB), A. Salgundi (IITB), H. Kumar (IITB), V. Bhalerao (IITB), G.C. Anupama(IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of GRB 230510A detected by Fermi (Fermi GBM team, GCN 33751, 33766) and Swift (Eyles-Ferris et al., GCN 33752) with 0.7m GROWTH-India Telescope (GIT). GIT automatically triggered at 19:35:39 UT, i.e., 7.5 hours after the Fermi GBM trigger. We obtained 3 frames of 300s each in the r' band. We search individual images and the stacked image for an afterglow, at the position reported by P.A. Evans et al. (GCN #33756). We do not detect the optical afterglow emission that was detected by S.Q. Jiang et al., (GCN #33761). Our upper limits on the magnitude of the afterglow are:
-------------------------------------------------------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) |
-------------------------------------------------------------------------------------------------------------------
2460075.3164274 | 7.52 | 300 | r' | > 18.77 |
2460075.32027526 | 7.62 | 300 | r' | > 18.81 |
2460075.32398713 | 7.71 | 300 | r' | > 18.90 |
2460075.320207265 | 7.61 (mid) | 3x300 (stacked) | r' | > 19.87 |
------------------------------------------------------------------------------------------------------------------
The results are consistent with other afterglow observations reported by S.Q. Jiang et al., GCN #33761; S.Q. Jiang et al., GCN #33764; A. Belles et al., GCN #33774; R. Strausbaugh at al., GCN #33776. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular 33776
Subject
GRB 230510A: LCOGT Optical Upper Limit
Date
2023-05-12T00:51:38Z (3 years ago)
From
Robert Strausbaugh at University of Minnesota <rstrausb@umn.edu>
R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:
We observed the GRB 230510A (Eyles-Ferris et al., GCN 33752) field
with the LCOGT
1-meter Sinistro instrument at the Teide Observatory, Tenerife site, on May
11, from 03:03 to 03:36 UT (corresponding to 14.95 to 15.50 hours from the
GRB trigger time) with the SDSS r and i filters.
We performed a series of 3x300s exposures in each band. We do not detect a
source within the Swift-XRT enhanced error region (Evans et al., GCN 33756)
in either band, consistent with fading from the optical afterglow candidate
(Jiang et al., GCN 33761).
The following upper limits are calculated using the PanSTARRS catalog as
reference:
r > 21.5
i > 19.8
These magnitudes are not corrected for galactic extinction.
GCN Circular 33774
Subject
GRB 230510A: Swift/UVOT Observations
Date
2023-05-11T22:28:10Z (3 years ago)
From
Alexander Belles at PSU <aub1461@psu.edu>
A. Belles (PSU) and R. A. J. Eyles-Ferris (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230510A
72 s after the BAT trigger (Eyles-Ferris et al., GCN Circ. 33752).
A source consistent with the XRT position (Evans et al., GCN Circ. 33756)
is detected in the initial UVOT exposures.
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
wh_FC 72 222 150 18.90+/-0.10
u_FC 284 318 34 18.09+/-0.32
wh 4413 4613 200 19.33+/-0.11
v 4824 5024 200 18.97+/-0.32
b 4209 5690 241 19.31+/-0.17
u 5439 5638 199 19.10+/-0.24
w1 5234 5434 200 19.30+/-0.34
m2 5029 5228 199 >19.21
w2 4619 4819 200 >19.45
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.144 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 33766
Subject
GRB 230510A: Fermi GBM detection
Date
2023-05-11T08:36:05Z (3 years ago)
From
R. Hamburg at CNRS/IJCLab <rachel.k.hamburg@gmail.com>
C. Malacaria (ISSI) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 12:04:06.93 UT on 10 April 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230510A (trigger 705413051 / 230510503), which
was also detected by the Swift/BAT and Swift/XRT (Eyles-Ferris et al. 2023,
GCN 33752; Evans et al. 2023, GCN 33756). The GBM on-ground location is
consistent with the Swift position (GCN 33751).
The angle from the Fermi LAT boresight at the GBM trigger time is 14
degrees.
The GBM light curve shows a weaker peak followed about 100 s later
by a brighter peak, with a duration (T90) of about 177 s (50-300 keV).
The time-averaged spectrum from T0-4.1 s to T0+11.3 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.9 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 87 +/- 7 keV.
A Band function fits the spectrum equally well
with Epeak = 87 +/- 9 keV, alpha = -0.9 +/- 0.1 and beta = -3.8 +/- 3.2.
The event fluence (10-1000 keV) in this time interval is
(2.0 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+158 s in the 10-1000 keV band
is 12.4 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular 33764
Subject
GRB 230510A: Gaoyazi/GOT optical upper limit
Date
2023-05-11T07:17:27Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang, T.H. Lu, S.Y. Fu, X. Liu, D Xu (NAOC), Z.P. Zhu (NAOC, HUST), S.W. Luo, M.M. Yang, Z. K. Feng (GYZO, NAOC) report:
We observed the field of GRB 230510A detected by Swift (Eyles-Ferris et al., GCN 33752) and Fermi(Fermi GBM team, GCN 33751) with the GOT-0.5m telescope located at Gaoyazi, Xinjiang, China. Observations started at 18:48:27 UT on 2023-05-10, i.e., 6.7 hr after the Swift/BAT trigger, 40 x 90 s images were obtained in the Sloan r filter.
No optical source is detected in our stacked image at the enhanced XRT position (Evans et al., GCN 33756), down to a 3-sigma limiting magnitude r > 19.7 (AB) at 7.27 hr post-burst, calibrated with nearby PanSTARRS stars. The upper limit is consistent with our deeper detection at the Nanshan/NEXT (Jiang et al., GCN 33761).
GCN Circular 33762
Subject
GRB 230510A: CALET Gamma-Ray Burst Monitor detection
Date
2023-05-11T06:18:01Z (3 years ago)
From
Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>
S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The long GRB 230510A (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 33751; Swift detection: Eyles-Ferris et al., GCN Circ. 33752)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 12:06:22.60 UTC on 10 May 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1367755544/index.html).
The burst signal was seen by all CGBM detectors.
The burst light curve shows a multi-peaked structure that starts
at T-139.5 sec, peaks at T+19.6 sec, and ends at T+43.6 sec.
The T90 and T50 durations measured by the SGM data are 106.2 +/- 71.3 sec
and 13.1 +/- 0.7 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1367755544/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.
GCN Circular 33761
Subject
GRB 230510A: Nanshan/NEXT optical afterglow detection
Date
2023-05-11T03:06:34Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang, T.H. Lu, S.Y. Fu, X. Liu, D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 230510A detected by Swift (Eyles-Ferris et al., GCN 33752) and Fermi (Fermi GBM team, GCN 33751) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations started at 18:47:49.1 UT on 2023-05-10, i.e., 6.69 hr after the Swift/BAT trigger, and 12x200 s exposures have been obtained in the Sloan r-filter.
We detected an uncatalogued optical transient (OT) within the enhanced Swift/XRT error circle (Evans et al., GCN 33756) at coordinates
R.A. (J2000) = 21:12:32.87
Dec.(J2000) = +34:26:35:59
with an uncertainty of ~ 0.5 arcsec, and it has m(r) = 20.5 +/- 0.1 mag in the co-added image at 7.27 hr post-burst, calibrated with the nearby PanSTAR field. PanSTAR covers this position and is much deeper, but the OT is not present. We thus conclude that the OT is the optical afterglow of the burst.
GCN Circular 33757
Subject
GRB 230510A: Swift-XRT refined Analysis
Date
2023-05-10T21:19:36Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai
(INAF-IASFPA), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), S.
Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L.
Page (U. Leicester) report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 230510A, from 52 s to 23.0
ks after the BAT trigger. The data comprise 250 s in Windowed Timing
(WT) mode (the first 10 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode.
The late-time light curve (from T0+4.2 ks) can be modelled with a
power-law decay with a decay index of alpha=0.92 (+/-0.09).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.19 (+/-0.05). The
best-fitting absorption column is 2.53 (+0.17, -0.16) x 10^21 cm^-2,
in excess of the Galactic value of 1.9 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.99 (+0.13, -0.08)
and a best-fitting absorption column of 1.938 (+0.454, -0.025) x 10^21
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.5 x 10^-11 (4.8 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.938 (+0.454, -0.025) x 10^21 cm^-2
Galactic foreground: 1.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.99 (+0.13, -0.08)
If the light curve continues to decay with a power-law decay index of
0.92, the count rate at T+24 hours will be 0.035 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.7 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01167973.
This circular is an official product of the Swift-XRT team.
GCN Circular 33756
Subject
GRB 230510A: Enhanced Swift-XRT position
Date
2023-05-10T18:57:48Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1466 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 230510A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 318.13672, +34.44306 which is equivalent
to:
RA (J2000): 21h 12m 32.81s
Dec (J2000): +34d 26' 35.0"
with an uncertainty of 2.2 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 33752
Subject
GRB 230510A: Swift detection of a burst
Date
2023-05-10T12:44:51Z (3 years ago)
From
K.L. Page at U Leicester <klp5@leicester.ac.uk>
R. A. J. Eyles-Ferris (U Leicester), P. A. Evans (U Leicester),
J.D. Gropp (PSU), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), P. Romano (INAF-OAB), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB) and M. A. Williams (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:
At 12:06:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230510A (trigger=1167973). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 318.156, +34.443 which is
RA(J2000) = 21h 12m 37s
Dec(J2000) = +34d 26' 33"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 60 sec. The peak count rate
was ~5100 counts/sec (15-350 keV), at ~13 sec after the trigger.
The XRT began observing the field at 12:07:31.9 UT, 63.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 318.1314, 34.4424 which is equivalent to:
RA(J2000) = 21h 12m 31.54s
Dec(J2000) = +34d 26' 32.6"
with an uncertainty of 6.5 arcseconds (radius, 90% containment). This
location is 73 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
The initial flux in the 0.1 s image was 1.19e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 72 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.144.
This trigger was initially marked as matching a source in the BAT
ground catalogue: IGR J21117+3427, a known gamma-ray source. However,
the XRT localisation is more than 9 arcmin from the known position of
IGR J21117+3427, outside its error region of 3.5 arcmin (ATel 873).
This, together with the BAT transient monitor light-curve showing
little sign of variation suggests that this is in fact a new GRB.
Burst Advocate for this burst is R. A. J. Eyles-Ferris (raje1 AT leicester.ac.uk).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular 33751
Subject
GRB 230510A: Fermi GBM Final Real-time Localization
Date
2023-05-10T12:14:55Z (3 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 12:04:06 UT on 10 May 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230510A (trigger 705413051.934178 / 230510503).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 322.3, Dec = 31.0 (J2000 degrees, equivalent to J2000 21h 29m, 31d 00'), with a statistical uncertainty of 2.6 degrees.
The angle from the Fermi LAT boresight is 14.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_skymap_all_bn230510503.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_healpix_all_bn230510503.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_lc_medres34_bn230510503.gif